A ski-boot assembly with a rigid upper, an incomplete sole of the upper, and a front and/or rear means for cooperation with a removable sole assembly. A first removable sole assembly includes at least one curb part and a bearing plat; and a cooperation means that complements the front and/or rear cooperation means of the incomplete sole to form a boot with a sole whose configuration corresponds to standard ISO 5355 for Alpine ski-boots. A second removable sole assembly has at least one curb part and a sole cooperation means that complements the front and/or rear cooperation means of the incomplete sole to form a boot with a sole whose configuration corresponds substantially to standard ISO 9523 for touring boots. A locking means locks the first or the second removable sole assembly under the incomplete sole of the upper and includes a manual actuating means.